During my stream when I was brainstorming all this, I had Zecora pegged for the hermit briefly as well, back when I had Spike as the Magician and Twilight as the Priestess (because I was trying to be gender-true), but I realized through some research that the Magician doesn't HAVE to be physically male so long as his approach to knowledge is analytical - likewise, the priestess's wisdom had to be represented by "heart knowledge" - but was no less well informed than the Magician. The only character that can rival Twilight in knowledge is Zecora.
Thus Zecora was out for the Hermit. She wasn't quite right for it anyway - because the hermit makes the choice to be alone, and would never reach out to anyone for any reason. He also would NEVER offer advice or help, because he is completely wrapped up in himself. That's just not her! - so as I approached him, I was taken by the fact that one of his symbols is the moon, but Luna didn't work, as she is also social (though awkward). But then we had that time where she took the journey of walking by herself, and while the results were poor, it was an important time for her.
Since the Hermit is on a journey of self discovery - and segregates himself from the world's ways in order to accomplish it, there is only one character who does this in the whole show - Luna as NMM.